cdpwest / hibernate-generic-dao

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Search for Collection-Members fails #30

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago
Scenario:
DB entity "Person" has a "many-to-many" assoziation "friends" which are
"Person".

How to search for persons which have a special friend X.

First I tried Filter.some("friends", Collection<X>) which results in
"**INVALID VALUE - NOT A FILTER: ..." .

I solved this by by doing something like 
Filter.some("friends", Filter.in("id", Collection<X.id()>))

Original issue reported on code.google.com by c.dittbe...@digitec.de on 13 May 2009 at 1:46

GoogleCodeExporter commented 8 years ago
Are you saying that Filter.some("friends", Filter.in("id", Collection<X.id()>)) 
did 
work successfully and gave you the results you wanted?

Also, what do you mean by the "Collection<...>" syntax?

I'm sorry that the usage is sort of confusing for these filters. Hopefully I 
can get 
some better examples up sometime. In the mean time, both of the following 
options 
should work for your case. If not, then there may be a bug in the framework.

Filter.some("friends", Filter.equal("", X);
Filter.some("friends", Filter.equal("id", X.getId());

There is also a blog entry that has some more examples: http://java-generic-
dao.blogspot.com/2008/12/search-capability-needs-to-be-able-to.html

Original comment by dwolvert on 13 May 2009 at 7:23

GoogleCodeExporter commented 8 years ago
>Are you saying that Filter.some("friends", Filter.in("id", 
Collection<X.id()>)) did 
>work successfully and gave you the results you wanted?

Yes it does.

Collection<X.id()> is my shortcut of:

List<Integer> idList = new ArrayList<Integer>(); 
for (X x : getCollectionOfTypeX()) { idList.add(x.getId());}
search.addFilter(Filter.some("friends", Filter.in("id", idList))));
search.addFetch("friends")

this works well but is "ugly" code. I prefer the example of your blog entry:

Filter.some("friends", Filter.in("", collectionOfFriends))

I think it could be more distinguishable if you provide something like
Filter.in(Collection<?> collection).

BTW many thanks for this very helpfull framework.

Original comment by c.dittbe...@digitec.de on 14 May 2009 at 5:16

GoogleCodeExporter commented 8 years ago
Will not change API. Will add more examples of Filters to the documentation.

Original comment by dwolvert on 27 May 2009 at 6:47